<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style>
     #div01{
		 width:510px;
		 height:200px;
		 background-color:#F09;
		 float:left;
		 margin-bottom:10px;
	 }
	 #div02{
		 width:200px;
		 height:200px;
		 background-color:#CCF;
		 float:left;
		 margin-bottom:10px;
		 margin-right:10px;
	 }
	 #div03{
		 width:300px;
		 height:200px;
		 background-color:#F99;
		 float:left;
		 margin-bottom:10px;
	 }
	 #div04{
		 width:510px;
		 height:200px;
		 background-color:#FCF;
		 float:left;
	 }
	 #abc{
		 margin:auto;
		 width:510px;
	 }

</style>
</head>

<body>
<div id="abc" align="center">
    <div id="div01">我不动</div>
    <div id="div02">向左浮动</div>
    <div id="div03">向右浮动</div>
    <div id="div04">底部</div>
</div>
</body>
</html>
